1. Field of the Invention
The present invention relates to a junction-gate type static induction thyristor for use in a high-voltage pulse generator.
2. Description of the Background Art
A technique for performing laser oscillation and gas decomposition using plasma generated by discharging a high-voltage pulse has conventionally been studied. In this technique, it is desired to use a high-voltage short pulse, however, to generate such a high-voltage short pulse, a large-scale high-voltage pulse generator has been required since a high-voltage power supply, for example, needs to be provided therein.
On the other hand, a small, inexpensive high-voltage pulse generator for generating a high-voltage short pulse is disclosed in “Analysis of actions of Static Induction Thyristor on Inductive Energy Storage type power supply” Naohiro Shimizu et al., 16th Symposium of Static Induction Devices, ISSN 1340-5853, SSID-03-8, pp. 49-53 (Jun. 13, 2003). A circuit employed as the high-voltage pulse generator disclosed in this document mainly makes use of a turn-off action of a static induction thyristor, which is called an IES (Inductive Energy Storage) circuit.
This IES circuit has an outstanding advantage in that it can be constructed compactly at low costs, however, a specific configuration of a static induction thyristor (hereinafter also referred to as “SIThy”) used therein has not fully been studied. Therefore, depending on operating conditions of the high-voltage pulse generator, there are some cases in which an SIThy is broken down and in which a high-voltage short pulse cannot be generated. In some other cases, an SIThy for use in the IES circuit is designed redundantly more than necessary, resulting in size increase, thus increasing manufacturing costs, or frequencies generated cannot be increased due to great loss in the SIThy.